SCHEDULE 13G

CUSIP No.

449778109

Names of Reporting Persons

Vivo Capital IX, LLC

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

0 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

449778109

Names of Reporting Persons

Vivo Capital Fund IX, L.P.

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

Aggregate Amount Beneficially Owned by Each Reporting Person

0.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

0 %

Type of Reporting Person (See Instructions)

SCHEDULE 13G

CUSIP No.

449778109

Names of Reporting Persons

Vivo Opportunity, LLC

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 3,157,894.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 3,157,894.00
8	Shared Dispositive Power 0.00

Aggregate Amount Beneficially Owned by Each Reporting Person

3,157,894.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

4.6 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person: The number represents 3,157,894 shares of common stock, par value $ 0.001 per share (the "Common Stock") of IO Biotech, Inc. (the "Issuer"), issuable upon exercise of certain warrants. All securities are held of record by Vivo Opportunity Fund Holdings, L.P. Vivo Opportunity, LLC is the general partner of Vivo Opportunity Fund Holdings, L.P. Based on the sum of (i) 65,880,914 shares of Common Stock outstanding of the Issuer as of August 11, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q, filed with the Securities and Exchange Commission (the "SEC") on August 14, 2025, and (ii) 3,157,894 shares of Common Stock, issuable upon exercise of the warrants held of records by Vivo Opportunity Fund Holdings, L.P.

SCHEDULE 13G

CUSIP No.

449778109

Names of Reporting Persons

Vivo Opportunity Fund Holdings, L.P.

Check the appropriate box if a member of a Group (see instructions)

(a)

(b)

Sec Use Only

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 3,157,894.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 3,157,894.00
8	Shared Dispositive Power 0.00

Aggregate Amount Beneficially Owned by Each Reporting Person

3,157,894.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in row (9)

4.6 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person: The number represents 3,157,894 shares of Common Stock of the Issuer, issuable upon exercise of certain warrants. All securities are held of record by Vivo Opportunity Fund Holdings, L.P. Vivo Opportunity, LLC is the general partner of Vivo Opportunity Fund Holdings, L.P. Based on the sum of (i) 65,880,914 shares of Common Stock outstanding of the Issuer as of August 11, 2025, as reported in the Issuer's Quarterly Report on Form 10-Q, filed with the SEC on August 14, 2025, and (ii) 3,157,894 shares of Common Stock, issuable upon exercise of the warrants held of records by Vivo Opportunity Fund Holdings, L.P.

SCHEDULE 13G

Item 1.

(a)

Name of issuer:

IO Biotech, Inc.

(b)

Address of issuer's principal executive offices:

Ole MaalOes Vej 3, Copenhagen N, Denmark, DK-2200.

Item 2.

(a)

Name of person filing:

Vivo Capital IX, LLC Vivo Capital Fund IX, L.P. Vivo Opportunity, LLC Vivo Opportunity Fund Holdings, L.P.

(b)

Address or principal business office or, if none, residence:

192 Lytton Avenue, Palo Alto, CA 94301

(c)

Citizenship:

Delaware limited liability company.

(d)

Title of class of securities:

Common stock, par value $0.001 per share

(e)

CUSIP No.:

449778109

Item 3.

If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:

(a)

Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);

(b)

Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);

(c)

Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);

(d)

Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);

(e)

An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);

(f)

An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);

(g)

A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);

(h)

A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i)

A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j)

A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:

(k)

Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).

Item 4.

Ownership

(a)

Amount beneficially owned:

VIVO CAPITAL IX, LLC : 0 VIVO CAPITAL FUND IX, L.P.: 0 VIVO OPPORTUNITY, LLC: 3,157,894 SHARES VIVO OPPORTUNITY FUND HOLDINGS, L.P. 3,157,894 SHARES

(b)

Percent of class:

VIVO CAPITAL IX, LLC: 0% VIVO CAPITAL FUND IX, L.P.: 0% VIVO OPPORTUNITY, LLC: 4.6% VIVO OPPORTUNITY FUND HOLDINGS, L.P.: 4.6%

(c)

Number of shares as to which the person has:

(i) Sole power to vote or to direct the vote:

VIVO CAPITAL IX, LLC : 0 VIVO CAPITAL FUND IX, L.P.: 0 VIVO OPPORTUNITY, LLC: 3,157,894 shares VIVO OPPORTUNITY FUND HOLDINGS, L.P. 3,157,894 shares

(ii) Shared power to vote or to direct the vote:

(iii) Sole power to dispose or to direct the disposition of:

VIVO CAPITAL IX, LLC : 0 VIVO CAPITAL FUND IX, L.P.: 0 VIVO OPPORTUNITY, LLC: 3,157,894 shares VIVO OPPORTUNITY FUND HOLDINGS, L.P. 3,157,894 shares

(iv) Shared power to dispose or to direct the disposition of:

Item 5.

Ownership of 5 Percent or Less of a Class.

Ownership of 5 percent or less of a class

Item 6.

Ownership of more than 5 Percent on Behalf of Another Person.

Not Applicable

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.

Not Applicable

Item 8.

Identification and Classification of Members of the Group.

Not Applicable

Item 9.

Notice of Dissolution of Group.

Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Vivo Capital IX, LLC

Signature:	/s/ Frank Kung
Name/Title:	Frank Kung/Managing Member
Date:	11/14/2025

Vivo Capital Fund IX, L.P.

Signature:	/s/ Frank Kung
Name/Title:	Frank Kung/Managing Member of Vivo Capital IX, LLC, General Partner
Date:	11/14/2025

Vivo Opportunity, LLC

Signature:	/s/ Kevin Dai
Name/Title:	Kevin Dai/Managing Member
Date:	11/14/2025

Vivo Opportunity Fund Holdings, L.P.

Signature:	/s/ Kevin Dai
Name/Title:	Kevin Dai/Managing Member of Vivo Opportunity, LLC, General Partner
Date:	11/14/2025